According to invoice date of 8/26/2010 Order No. 100826-964438 Customer No. 761327 I purchased a toner cartridge (Product COM106) for my Canon MF6540 copier. Installed a few days ago, it worked fine for approximately 500 copies and then began dumping toner making about half the copie page black. I have done everything I know to correct the problem, cleaning the cartridge and all elements of my copier. Nothing works. The cartridge has failed and is a total loss. I would appreciate a replacement, Sincerely, Donald E. Campbell read full review »